/*
* Copyright © 2010 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/**
* \file brw_wm_channel_expressions.cpp
*
* Breaks vector operations down into operations on each component.
*
* The 965 fragment shader receives 8 or 16 pixels at a time, so each
* channel of a vector is laid out as 1 or 2 8-float registers. Each
* ALU operation operates on one of those channel registers. As a
* result, there is no value to the 965 fragment shader in tracking
* "vector" expressions in the sense of GLSL fragment shaders, when
* doing a channel at a time may help in constant folding, algebraic
* simplification, and reducing the liveness of channel registers.
*
* The exception to the desire to break everything down to floats is
* texturing. The texture sampler returns a writemasked masked
* 4/8-register sequence containing the texture values. We don't want
* to dispatch to the sampler separately for each channel we need, so
* we do retain the vector types in that case.
*/
extern "C" {
#include "main/core.h"
#include "brw_wm.h"
}
#include "glsl/ir.h"
#include "glsl/ir_expression_flattening.h"
#include "glsl/glsl_types.h"
class ir_channel_expressions_visitor : public ir_hierarchical_visitor {
public:
ir_channel_expressions_visitor()
{
this->progress = false;
this->mem_ctx = NULL;
}
ir_visitor_status visit_leave(ir_assignment *);
ir_rvalue *get_element(ir_variable *var, unsigned int element);
void assign(ir_assignment *ir, int elem, ir_rvalue *val);
bool progress;
void *mem_ctx;
};
static bool
channel_expressions_predicate(ir_instruction *ir)
{
ir_expression *expr = ir->as_expression();
unsigned int i;
if (!expr)
return false;
for (i = 0; i < expr->get_num_operands(); i++) {
if (expr->operands[i]->type->is_vector())
return true;
}
return false;
}
bool
brw_do_channel_expressions(exec_list *instructions)
{
ir_channel_expressions_visitor v;
/* Pull out any matrix expression to a separate assignment to a
* temp. This will make our handling of the breakdown to
* operations on the matrix's vector components much easier.
*/
do_expression_flattening(instructions, channel_expressions_predicate);
visit_list_elements(&v, instructions);
return v.progress;
}
ir_rvalue *
ir_channel_expressions_visitor::get_element(ir_variable *var, unsigned int elem)
{
ir_dereference *deref;
if (var->type->is_scalar())
return new(mem_ctx) ir_dereference_variable(var);
assert(elem < var->type->components());
deref = new(mem_ctx) ir_dereference_variable(var);
return new(mem_ctx) ir_swizzle(deref, elem, 0, 0, 0, 1);
}
void
ir_channel_expressions_visitor::assign(ir_assignment *ir, int elem, ir_rvalue *val)
{
ir_dereference *lhs = ir->lhs->clone(mem_ctx, NULL);
ir_assignment *assign;
/* This assign-of-expression should have been generated by the
* expression flattening visitor (since we never short circit to
* not flatten, even for plain assignments of variables), so the
* writemask is always full.
*/
assert(ir->write_mask == (1 << ir->lhs->type->components()) - 1);
assign = new(mem_ctx) ir_assignment(lhs, val, NULL, (1 << elem));
ir->insert_before(assign);
}
ir_visitor_status
ir_channel_expressions_visitor::visit_leave(ir_assignment *ir)
{
ir_expression *expr = ir->rhs->as_expression();
bool found_vector = false;
unsigned int i, vector_elements = 1;
ir_variable *op_var[3];
if (!expr)
return visit_continue;
if (!this->mem_ctx)
this->mem_ctx = ralloc_parent(ir);
for (i = 0; i < expr->get_num_operands(); i++) {
if (expr->operands[i]->type->is_vector()) {
found_vector = true;
vector_elements = expr->operands[i]->type->vector_elements;
break;
}
}
if (!found_vector)
return visit_continue;
/* Store the expression operands in temps so we can use them
* multiple times.
*/
for (i = 0; i < expr->get_num_operands(); i++) {
ir_assignment *assign;
ir_dereference *deref;
assert(!expr->operands[i]->type->is_matrix());
op_var[i] = new(mem_ctx) ir_variable(expr->operands[i]->type,
"channel_expressions",
ir_var_temporary);
ir->insert_before(op_var[i]);
deref = new(mem_ctx) ir_dereference_variable(op_var[i]);
assign = new(mem_ctx) ir_assignment(deref,
expr->operands[i],
NULL);
ir->insert_before(assign);
}
const glsl_type *element_type = glsl_type::get_instance(ir->lhs->type->base_type,
1, 1);
/* OK, time to break down this vector operation. */
switch (expr->operation) {
case ir_unop_bit_not:
case ir_unop_logic_not:
case ir_unop_neg:
case ir_unop_abs:
case ir_unop_sign:
case ir_unop_rcp:
case ir_unop_rsq:
case ir_unop_sqrt:
case ir_unop_exp:
case ir_unop_log:
case ir_unop_exp2:
case ir_unop_log2:
case ir_unop_bitcast_i2f:
case ir_unop_bitcast_f2i:
case ir_unop_bitcast_f2u:
case ir_unop_bitcast_u2f:
case ir_unop_i2u:
case ir_unop_u2i:
case ir_unop_f2i:
case ir_unop_f2u:
case ir_unop_i2f:
case ir_unop_f2b:
case ir_unop_b2f:
case ir_unop_i2b:
case ir_unop_b2i:
case ir_unop_u2f:
case ir_unop_trunc:
case ir_unop_ceil:
case ir_unop_floor:
case ir_unop_fract:
case ir_unop_round_even:
case ir_unop_sin:
case ir_unop_cos:
case ir_unop_sin_reduced:
case ir_unop_cos_reduced:
case ir_unop_dFdx:
case ir_unop_dFdy:
case ir_unop_bitfield_reverse:
case ir_unop_bit_count:
case ir_unop_find_msb:
case ir_unop_find_lsb:
for (i = 0; i < vector_elements; i++) {
ir_rvalue *op0 = get_element(op_var[0], i);
assign(ir, i, new(mem_ctx) ir_expression(expr->operation,
element_type,
op0,
NULL));
}
break;
case ir_binop_add:
case ir_binop_sub:
case ir_binop_mul:
case ir_binop_div:
case ir_binop_mod:
case ir_binop_min:
case ir_binop_max:
case ir_binop_pow:
case ir_binop_lshift:
case ir_binop_rshift:
case ir_binop_bit_and:
case ir_binop_bit_xor:
case ir_binop_bit_or:
case ir_binop_less:
case ir_binop_greater:
case ir_binop_lequal:
case ir_binop_gequal:
case ir_binop_equal:
case ir_binop_nequal:
for (i = 0; i < vector_elements; i++) {
ir_rvalue *op0 = get_element(op_var[0], i);
ir_rvalue *op1 = get_element(op_var[1], i);
assign(ir, i, new(mem_ctx) ir_expression(expr->operation,
element_type,
op0,
op1));
}
break;
case ir_unop_any: {
ir_expression *temp;
temp = new(mem_ctx) ir_expression(ir_binop_logic_or,
element_type,
get_element(op_var[0], 0),
get_element(op_var[0], 1));
for (i = 2; i < vector_elements; i++) {
temp = new(mem_ctx) ir_expression(ir_binop_logic_or,
element_type,
get_element(op_var[0], i),
temp);
}
assign(ir, 0, temp);
break;
}
case ir_binop_dot: {
ir_expression *last = NULL;
for (i = 0; i < vector_elements; i++) {
ir_rvalue *op0 = get_element(op_var[0], i);
ir_rvalue *op1 = get_element(op_var[1], i);
ir_expression *temp;
temp = new(mem_ctx) ir_expression(ir_binop_mul,
element_type,
op0,
op1);
if (last) {
last = new(mem_ctx) ir_expression(ir_binop_add,
element_type,
temp,
last);
} else {
last = temp;
}
}
assign(ir, 0, last);
break;
}
case ir_binop_logic_and:
case ir_binop_logic_xor:
case ir_binop_logic_or:
ir->print();
printf("\n");
assert(!"not reached: expression operates on scalars only");
break;
case ir_binop_all_equal:
case ir_binop_any_nequal: {
ir_expression *last = NULL;
for (i = 0; i < vector_elements; i++) {
ir_rvalue *op0 = get_element(op_var[0], i);
ir_rvalue *op1 = get_element(op_var[1], i);
ir_expression *temp;
ir_expression_operation join;
if (expr->operation == ir_binop_all_equal)
join = ir_binop_logic_and;
else
join = ir_binop_logic_or;
temp = new(mem_ctx) ir_expression(expr->operation,
element_type,
op0,
op1);
if (last) {
last = new(mem_ctx) ir_expression(join,
element_type,
temp,
last);
} else {
last = temp;
}
}
assign(ir, 0, last);
break;
}
case ir_unop_noise:
assert(!"noise should have been broken down to function call");
break;
case ir_binop_bfm: {
/* Does not need to be scalarized, since its result will be identical
* for all channels.
*/
ir_rvalue *op0 = get_element(op_var[0], 0);
ir_rvalue *op1 = get_element(op_var[1], 0);
assign(ir, 0, new(mem_ctx) ir_expression(expr->operation,
element_type,
op0,
op1));
break;
}
case ir_binop_ubo_load:
assert(!"not yet supported");
break;
case ir_triop_lrp:
case ir_triop_bitfield_extract:
for (i = 0; i < vector_elements; i++) {
ir_rvalue *op0 = get_element(op_var[0], i);
ir_rvalue *op1 = get_element(op_var[1], i);
ir_rvalue *op2 = get_element(op_var[2], i);
assign(ir, i, new(mem_ctx) ir_expression(expr->operation,
element_type,
op0,
op1,
op2));
}
break;
case ir_triop_bfi: {
/* Only a single BFM is needed for multiple BFIs. */
ir_rvalue *op0 = get_element(op_var[0], 0);
for (i = 0; i < vector_elements; i++) {
ir_rvalue *op1 = get_element(op_var[1], i);
ir_rvalue *op2 = get_element(op_var[2], i);
assign(ir, i, new(mem_ctx) ir_expression(expr->operation,
element_type,
op0->clone(mem_ctx, NULL),
op1,
op2));
}
break;
}
case ir_unop_pack_snorm_2x16:
case ir_unop_pack_snorm_4x8:
case ir_unop_pack_unorm_2x16:
case ir_unop_pack_unorm_4x8:
case ir_unop_pack_half_2x16:
case ir_unop_unpack_snorm_2x16:
case ir_unop_unpack_snorm_4x8:
case ir_unop_unpack_unorm_2x16:
case ir_unop_unpack_unorm_4x8:
case ir_unop_unpack_half_2x16:
case ir_binop_vector_extract:
case ir_triop_vector_insert:
case ir_quadop_bitfield_insert:
case ir_quadop_vector:
assert(!"should have been lowered");
break;
case ir_unop_unpack_half_2x16_split_x:
case ir_unop_unpack_half_2x16_split_y:
case ir_binop_pack_half_2x16_split:
assert("!not reached: expression operates on scalars only");
break;
}
ir->remove();
this->progress = true;
return visit_continue;
}